As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT CRUISE FLIGHT AT 41,000 FT HEARD A LOUD BANG & CABIN ALTITUDE WAS CLIMBING AT A RATE IN EXCESS OF 2000 FPM. UPON INITIAL INSPECTION BY MX AFTER AN UNEVENTFUL LANDING, IT WAS DISCOVER THAT THE COOLING TURBINE EXIT DUCT PN 25-8VF565-1A HAD BECOME SEPARATED FROM THE COOLING TURBINE. PART TIME IN SERVICE SINCE LAST MX WAS 2.2 HOURS & 1 LANDING.